Cut chicken into 1 inch cubes, smaller is fine, just be sure they are all the same size. In a large bowl whisk the tikka paste, yogurt, lemon, garlic and milk. Make sure the tikka paste is mixed in well, you may need to use a fork to mash any chunks. Add the chicken to the bowl and marinate for 10 minutes - 24 hours (any time in between is great). Keep the bowl covered and in the fridge for the duration of marinating.
Preheat oven to 375º. Drain and rinse chickpeas, add them to a baking tray with diced bell peppers. In a small bowl mix seasonings. Drizzle 1 tsp olive oil over the veggies and then sprinkle the seasoning, rub in so everything is evenly coated. Place in the oven for 10-15 minutes until the peppers are softened *keep an eye on them, oven temps vary greatly*
Dice up all the other salad toppings, tomato, onion, romaine. Set aside. In a large skillet heat up 1 Tbsp oil on medium heat, add in the marinated chicken. Cook the chicken for about 10-14 minutes, turning a few times for an even cook or until it's no longer pink and 165º internally.
While the chicken is cooking, blend the dressing in a small blender or food processor and set aside. Once the chicken is finished cooking, assemble the salad. Start with romaine, add onion, tomato, chickpeas/pepper mix, chicken and drizzle with dressing. Enjoy!